Eyebrow-raising writer (6)
I believe the answer is:
pencil
'writer' is the definition.
(something which writes)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for pencil that I've seen before include "American bureaucrat -- purple niches (anag)" , "Drawing instrument" , "Graphite stick" , "implement in case?" , "One doing boring clerical work?" .)